﻿function HtmlToPDF(pdfName, target) {
    target.addClass('whitearea')
    if (pdfName == '' || pdfName == undefined) pdfName = "content";
    html2canvas(target, {
        onrendered: function (canvas) {
            var contentWidth = canvas.width;
            var contentHeight = canvas.height;
            console.log(contentWidth);
            console.log(contentHeight);
            //一页pdf显示html页面生成的canvas高度;
            var pageHeight = contentWidth / 592.28 * 841.89;
            //var pageHeight = contentHeight;
            //未生成pdf的html页面高度
            var leftHeight = contentHeight;
            //页面偏移
            var position = 0;
            //a4纸的尺寸[595.28,841.89]，html页面生成的canvas在pdf中图片的宽高
            var imgWidth = 595.28;
            var imgHeight = 592.28 / contentWidth * contentHeight;
            //var imgHeight = contentHeight;

            var pageData = canvas.toDataURL('image/jpeg', 1.0);

            var pdf = new jsPDF('', 'mm', 'a4');

            //有两个高度需要区分，一个是html页面的实际高度，和生成pdf的页面高度(841.89)
            //当内容未超过pdf一页显示的范围，无需分页
            if (leftHeight < pageHeight) {
                pdf.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight);
            } else {
                while (leftHeight > 0) {
                    pdf.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight)
                    leftHeight -= pageHeight;
                    position -= 841.89;
                    //避免添加空白页
                    if (leftHeight > 0) {
                        pdf.addPage();
                    }
                }
            }
            pdf.save(pdfName + ".pdf");
        }
    })
}
